Design Features
During the operation, the tools are exposed to high pressure and abrasives, which require the highest quality steel, having proper heat treatment and sometimes special coating preventing the tools from wearing or sticking. Some applications such as household chemical product require using plastic inserts for additional punch pressing part protection.
Unique Coatings
In order to improve the surface hardness of tablet compression tooling, different coatings can be applied. The benefits include higher wear resistance, decreased friction, minimized punch seizure and higher corrosion resistance and anti-adhesion properties.
Galvanic Chrome Coating
This is the most popular way of surface protection which has been proven in many standard applications. The coating is applied by electrolytic method in the sulphate bath. The coating thickness is about 5 microns.
PVD Coating
This is vapour metal deposit process. Compared to the galvanic coating, the benefits of PVD coatings are as follows: better stability, contour prevention and wear protection.
CrN (Chromium Nitride) Coating
This is a specific PVD Coating. The obtained surface properties are much better than those obtained by the commonly used galvanic chrome plating: surface hardness is 3-4 times higher, low sticking susceptibility comparable with galvanic coating, higher wear protection and higher quality/price ratio.
TiN (Titanium Nitride) or TiAIN (Aluminum – Titanium Nitride) Coating
Comparable with CrN coating regarding sticking and susceptibility. Other benefits are: surface hardness is as much as 4 times higher than galvanic coating, higher wear protection than CrN coating and very smooth layer with low roughness.
DLC (Diamond Like Carbon) Coating
As the name implies, DLC provides some of the properties of diamonds to metal surface finishes. Benefits include: very abrasive resistant coating, long lasting anti-sticking properties, high “slickness”, very good for problematic products such as effervescent tablets, surface hardness is as much as 6 times higher than with galvanic coating, very high quality / price ratio.
